Dark Entropy

Dark Entropy is a debuff from the damage phases of the Prophecy dungeon's final boss, Kell Echo. Guardians gain one stack every two seconds while they are away from the boss. Standing near Kell Echo removes stacks, and the safe distance is shown by a ring around the boss. Kell Echo periodically teleports, and its portal attack sends the player back to the start of the arena, which puts them further from the boss and adds stacks. Reaching 10 stacks kills the player instantly.